HEALTH MATTERS DR. PAUL DONOHUE Q. I have heard of organ-cleansing diets several times in the past months. Some people I know have gone on these diets to cleanse the liver, kidneys and bowels. Some have bought books that describe the diet. One person used a product for cleansing that can be purchased online. Do you know if these diets and products contribute to health? A. I firmly believe that nature made us in such a way that our organs and our digestive tracts cleanse themselves without our interference. Only if we become sick do our organs need outside help. Meddling with them unnecessarily is not a way to prevent illness. Much of this cleansing desire comes from times gone by, when it was believed that the bowel was poisoning us with toxins. That's not true. These are my opinions. You're welcome to accept or reject them. Q. After a bone density test, my physician prescribed Fosamax. I have heard that it has a serious side effect -- jaw decay. Would you take it? A. Almost all postmenopausal women have to contend with osteoporosis. The normal balance between bone building and bone breakdown is lost due to aging and a drop in estrogen production that occurs at menopause. That makes their bones fragile and easily broken. The hip bone and the backbones (vertebrae) are the ones most often fractured. Fosamax and its related drugs, such as Actonel and Boniva, are the most powerful fighters of osteoporosis and its complications. These drugs are the bisphosphonates. Osteonecrosis is bone death. The entire bone doesn't die; only a small portion disintegrates and crumbles. Bisphosphonate drugs can lead to jaw osteonecrosis. Most often this happens when the medicines are given in high doses in treatment of conditions like cancer. Even then it is a rare occurrence, and it is a rarer occurrence when the drugs are given in the doses used for osteoporosis. Jaw osteonecrosis is usually seen when a major dental procedure -- a tooth extraction, for example -- is done on a person taking a high dose of bisphosphonates. For that reason, it's wise to have major dental work done before starting a bisphosphonate drug. I wouldn't hesitate to take a bisphosphonate for osteoporosis. Men do get it, and they too require treatment. The common consequences of osteoporosis are far more intimidating to me than is the rare side effect of jaw osteonecrosis. Q. Since he was a young boy, my husband has had diabetes. He is 46 now. He has had bleeding in his right eye, and it has affected the vision in that eye. That's a complication of diabetes, isn't it? How does it happen? Will he eventually become blind? I have read that there's a vitamin combination that can prevent blindness. Would it work for him? A.Your husband has diabetic retinopathy, a common aftermath of type 1 diabetes, the kind that comes on in childhood and requires insulin for control. One kind of diabetic retinopathy involves the sprouting of new, fragile blood vessels in the retina. These vessels spontaneously break and bleed, and that leads to vision impairment. When blood sugar is strictly controlled, the chance of diabetic retinopathy lessens, but even with meticulous control it can happen. From this point on, your husband's eye doctor will examine him closely and often. The doctor can spot the formation of new blood vessels on the retina and can seal them off with a laser. That's one way to preserve vision. Of course, your husband must strive for as perfect control of his blood sugar as he can. That's the other way to preserve vision. The vitamin-mineral combination you read about isn't intended for diabetic retinopathy. It's designed for macular degeneration, an entirely different retinal problem. Q. I am 37 years old and try to stay physically fit. I exercise five times a week. For the past few months I have had pain in my tailbone when I sit. I blamed it on bike riding, but it hasn't gone after giving up biking. I haven't had any injury. My doctor has ordered an X-ray, but I have not followed through on that. What could be causing this pain? A. You make a case for pain coming from the coccyx (KOK-six), the end part of the spine. Soaking in a tub of warm water, taking an anti-inflammatory medicine such as Aleve and sitting on a padded, doughnut-shaped cushion can relieve the pain. Wearing a 3-inch-wide belt at mid-buttock level, next to the skin, provides a natural cushion for the coccyx. A doctor can inject the area with cortisone and lidocaine to dull the pain. The X-ray you have put off can confirm any coccyx abnormality. Send your question to Dr. Paul Donohue at P.O. Box 536475, Orlando, FL 32853-6475.